450 Diamond series help

Chip,

Lot’s going on here and I can’t give you 100%, only something to consider…

1)    Pics tell me the engine have some fresh paint –I never did like that as you really cannot see certain things that matter to a very trained eye. With that said, the best thing you can do as to an pre- “evaluation” is to be on the boat on a cold/cool day and  do an engine an  start –up,  “cold iron” condition and know 100% the engines were not stated in the previous 2-3 days.. If they were ( like for a minute or so a few hours earlier, then all bets are off…………..That engine starts on 3 things—Good batteries /connections so the engine cranks at 150 RPM or better, fuel at the injection pump, and Heat ( compression) and that one thing alone will tell you more about cylinder /valve condition  that any survey will. If you go the extra mile and video the start up with sond, that would me major for me to evaluate.

2)   Without really know what “fried” means, I can’t really tell you anything about the crank,  etc. But 99+% of the time, fried is related to an overheat  and not loss of oil. Maybe the oil line to the turbo went and it really just fried the turbo? Never seen  a crank  damaged in these situations ..

3)   Rebuild in the boat—Make no different n this engine as long as it was done right—Mid stop wet linered engine with simple to replace pistons, liners, bearings, etc.—It all comes down to the right mechanic, access,  and using genuine Cummins parts

4)   4000 hrs——— To mean,  that means something  good———Someone was taking care of things and that the engines were not being run that hard.. Your rebuild on the other engine could have been just  an “unlucky occurrence” with the wrong person driving the boat that was not aware of something going on?  Don’t know, but I have plenty of these engines that have been run easy that have well over 20000 hours and they still run great. But , is this boat going to run a trawler type speeds, or on plane about 15-18 Knots—That make a a big difference for both engine s from the day you owe it forward————What are your plans that way ??.

5)   Buying genuine Cummins factor new non-exchange RECONs will set you back about  $30K per.. You can sell your good running  engines  for  $6-10K apiece on the open market,, But, don’t forget the labor for the R&R.

6)   Personally, I would not rebuild unless you are you own “motivated & experienced”  self-taught mechanic,  and you want the exercise & had the time..  $5-10 K per in parts depending on how deep you want to go..

Things that you need to understand on in these links—All boats and engines in this class apply here—Cat, Volvo, JD, etc.. ..

• Cummins Marine Aftercooler Maintenance
• “Marine Age” the REAL age of a Marine Diesel Engine
• Continuous Duty – A Different Perspective
• Engine Life vs. Engine Loading
• Low Speed Running & “Break-In” of Marine Diesels
• Choosing the Right Diesel
• The Cummins 6CTA 8.3 Marine Engine Story
• Engine Life
• Fuel and Horsepower